Fluid detergent products, such as liquids, gels, pastes and the like, are preferred by many consumers over solid detergents. Fluid detergent products may contain surfactants, e.g., anionic surfactants, and one or more solvents, in addition to water. Solvents may provide a variety of benefits: solvents may allow for the formulation of anionic surfactant-rich surfactant systems, particularly for compacted fluid detergents; solvents may adjust the viscosity of a formulation; solvents may allow for the formulation of an isotropic and physically stable formulation; and solvents may allow for the formulation of enzymes, polymers, bleach, chelants, and other ingredients that improve cleaning. Solvents may also be used to formulate stable, shippable, anionic surfactant concentrates, which may be combined downstream with other detergent ingredients to form a final detergent product. Also, some fluid detergent forms, such as fluid unit dose articles, may contain high levels of anionic surfactant and high levels of solvent, such as 30% or more solvent by weight of the total formulation.
Known solvents for use in fluid detergent formulations include 1,2-propane diol (p-diol) (also called propylene glycol), ethanol, diethylene glycol (DEG), 2-methyl-1,3-propanediol (MPD), dipropylene glycol (DPG), oligamines (e.g., diethylenetriamine (DETA), tetraethylenepentamine (TEPA), and glycerine (which may, for example, be used in fluid unit dose articles). However, these known solvents all have significant disadvantages, particularly if used at increased levels, including cost, formulatability, color, dissolution rate, solubility/stability of film in certain fluid unit dose articles, and potential adverse effects on cleaning and/or whiteness.
For example, propylene glycol is known to degrade slowly in the presence of oxygen and therefore may require special storage. Metal contamination, acidic or basic contaminants and higher temperatures all accelerate the degradation reactions. Typical oxidation products are aldehydes, ketones, acids and dioxolanes. A strong odor, higher acidity, higher ultra-violet (UV)-absorption, or high color are indicators that a propylene glycol has started to degrade.
Thus, there remains an ongoing need to identify new solvents that may allow for the formulation of increased concentrations of anionic surfactants in fluid detergent compositions, particularly compact fluid detergent compositions and concentrated surfactant pastes, and may address one or more of the disadvantages of known solvents discussed above.
Separately, the use of alkoxylated glycerine in detergent compositions is known. For example, a detergent composition comprising an ethoxylated glycerine compound represented by the following formula (A) and a fatty acid alkaline metal salt, represented by the formula B,
where R′ represents H or CH3, and each of n, m, and l independently represents an integer from 0 to 20; being m+n+l=2-60, preferably 10-45, and where R represents an alkyl or alkenyl group having C7-21, and M represents an alkaline metal, is known in the art. The benefits of this known composition include a saving in the amount of antifoaming agents, as well as better performance in skin irritation, oral toxicity and biodegradation, without a loss in detergency.
Another known liquid detergent composition contains from about 1% to about 90% of a surfactant selected from anionic, nonionic, and amphoteric surfactants and mixtures thereof, and a hydrotrope that is a mixture of an alcohol ethoxylate and a polyethylene glycol ether of glycerin, where the hydrotrope provides increased foam generation. The polyethylene glycol ether of glycerin has the following general formula (B):
where a+b+c has an average value of from about 2 to about 60, preferably from about 10 to about 45, more preferably from about 20 to about 30, and where R1, R2, and R3 may be the same or different and are selected from the group consisting of H, CH3, or C2H5.
Aqueous, concentrated dilutable liquid cleaning compositions comprising one or more anionic surfactants, one or more non-ionic surfactants, where the non-ionic surfactant comprises one or more polyethoxylated glycerine ester compounds, and an electrolyte, preferably in combination with one or more amphoteric surfactants, having a total active matter higher than 45 wt % based on the sum of the surfactants, are known. Such compositions are described as exhibiting a controllable viscosity profile that is satisfactory to the consumer while being easy to dilute.
Cleaning compositions containing a modified polyol having alkoxylation and amine capping units are also known.
Finally, cosmetic and personal care products containing glycereth-7, as an anhydrous solvent, are known.
It has been found that alkoxylated glycerine provides a better performing solvent in a fluid detergent product. Furthermore, it has been found that alkoxylated glycerine performs better than many existing solvents used in detergent formulations and surfactant pastes, such as propylene glycol and dipropylene glycol.